My TC18 has the same safety system. The first couple of times I started to get off and had the tractor stop running entirely, it annoyed me so much that I just got in the habit of always locking the brake and placing it in neutral, even when I plan to shut it off. It has to be in neutral to start it again anyway, and it's no problem to kick the brake pedal and unlock it the next time you start it up. The brake holds so good that if you forget and press the hydro pedal with the brake locked, it just stalls. I don't know how any of the other brands work, but NH got the safety stuff right.